Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 7

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  acidophilous oak forest
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Coppicing is uncommon in Poland; however, some remnants of a previously coppiced oak forest persist in the foothills of the Sudety Mountains (southern Poland). Some of these forests are considered as a kind of thermophilous oak forest, classified as habitat 91I0 in the European programme Natura 2000. As an example of previously coppiced sessile oak (Quercus petraea (Matt.) Liebl.) forest in Poland, the vegetation and environmental factors in the “Wąwoz Lipa” reserve (area 101 ha, altitude ca. 400 m a.s.l.) were surveyed. Canonical correspondence analysis showed a basic compositional gradient of vegetation related to the content of coarse fragments in the soil, light availability and soil pH. The number of species per plot was not correlated with any particular environmental variable; in general, the plant species number and cover decreased in the most exposed sites, where the heat load was highest. We hypothesize that the higher number of species in some plots was the results of an edge effect: this occurred in transitional zones between the most exposed sites, which work as refuges for light-demanding, drought-tolerant species, and less exposed sites, with vegetation typical of acidophilous oak forests. The land relief also allowed the spread of species typical of mesophilous forests, which found refuge in the shaded, wet gorges. Thus, the specific land relief, along with previous coppice management, allowed the coexistence, probably temporally, of species of plants considered typical of different habitats.
The paper presents the comparison of species diversity and evenness indices calculated for coexisting communities of aphids and ants. In six study areas, localised in Upper Silesia (Poland), representing acidophilous oak-forest (Molinio caeruleae – Quercetum roboris), moist meadow (Molinietum caeruleae) and xerothermic grassland (Sileno-Phleetum) the community structure of aphids and ants (species number and abundance) was determined. The number of ant nests and aphid colonies was determined by searching the squares of 25 m2 during vegetation seasons in 2006 and 2007. This provided the base to calculate the Shannon’s diversity index and evenness index of both groups. Spearman’s rank correlation analysis showed significant correlation only in the case of the number of species of both groups in a particular study area. It showed no significant correlation of values of diversity and evenness indices; however, considerable differences of values between both groups in various habitat types were recorded. The results are discussed with reference to the habitat history and maintenance, also reflecting the mutualistic relationship between ants and aphids.
In 2009 and 2010, monitoring of conservation status and future prospects of the forest communities of Quercetea robori-petraeae Br.-Bl. et R.Tx. 1943 class was conducted in the Sudetes and their foothills. 31 sites were selected. At each site, three phytosociological releves were collected. An important component of the global assessment of oak forest communities is the occurrence of synanthropic species as measured by three indicators: occurrence of alien species (kenophytes), occurrence of synanthropic native species (apophytes) and occurrence of geographically alien tree species. At most sites, alien species and native expansive species were not observed or were represented by single specimens. For each site and releve, the index of synanthropization was calculated. The main role in the synanthropization of the investigated acidophilous oak forests is played by apophytes. The values for the synanthropization index suggest that this process is not advanced. However. the impact of synanthropization on species richness and floristic diversity of communities within oak forests is noticeable.
This work presents characteristics of plant communities identified as forest habitats of European Ecological Natura 2000 Network in Oleśnica Śląska Forest Inspectorate. A fieldwork was carried out on the total area of 4 262.67 ha, which was pointed out as probable Natura 2000 forest habitats on the basis of the species composition of stands and forest habitat type. Data was collected in accordance with the Braun-Blanquet method in selected forest subsections. 121 relevés were used in the analysis. The fieldwork confirmed Natura 2000 habitats on the area of 1 761.4 ha. Finally, they represent 6.7% of the forest inspectorate area. The habitats in a good condition were found on the area of 293.7 ha (16.7%) and the degenerated habitats on the area of 1 467.7 ha (83.3%). 6 forest habitats represented by 7 forest associations were identified: Vaccinio uliginosi-Pinetum (91D0-2), Molinio caeruleae-Quercetum roboris (9190), Calamagrostio arundinaceae- Quercetum petraeae (9190), Fraxino-Alnetum (91E0-3), Ficario-Ulmetum minoris (91F0), Galio sylvatici-Carpinetum betuli (9170-1), Luzulo pilosae-Fagetum (9110-1). The area of elm-ash forests was the largest and the area of Scotch pine bog forest was the smallest. Among the other habitats the area of beech forests was also significant.
The paper summarizes fieldwork which was carried out on the proposed Natura 2000 area called Ostoja nad Bobrem, located in the south-west of Poland. The research confirmed the presence of natural habitats appearing in Annex I to the Habitat Directive. Among them there are particularly important priority habitats such as: species-rich Nardus grasslands on siliceous substrates in mountain areas (and submountain areas in Continental Europe *6230), Tilio-Acerion forests on slopes screes and ravines (*9180) and alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae *91E0).
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.